Canine Osteosarcoma Overview
Osteosarcoma is the most common bone tumor in dogs. Bone cancer usually affects older or giant breed dogs, but has been seen in younger dogs as well. It’s rare in cats. Although it is an aggressive cancer that can be found in any bone, it mostly develops in the limbs. Therefore, osteosarcoma steadily becomes more painful as it progresses.
Symptoms of Osteosarcoma
Dogs with Osteosarcoma in the limbs will show swelling at the developed site along with increased lameness. Sometimes, the first sign a dog has bone cancer is a fracture at the site of the tumor. Other signs depend upon the location of the cancer. For example, bone cancer of the spine could present neurological symptoms. Due to the high rate of metastasis (spread of tumor cells) to the lungs, X-rays are taken of both the chest and affected limb. Sometimes, bone scans are done of the other limbs as well.
The most common cause of death in dogs with osteosarcoma is the spreading of cancer to the lungs and other organs. As other tumors can show up in the limbs, a biopsy of the affected site may be the only way to confirm the presence of bone cancer.
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Since osteosarcoma is a painful, aggressive cancer with a high rate of metastasis, a positive diagnosis of bone cancer usually means the affected limb must be removed followed by chemotherapy and possible radiation. The more commonly used chemotherapy drugs include Carboplatin, Cisplatin and sometimes Doxorubicin. There are side effects associated with chemotherapy drugs, but the risk usually outweighs the benefits. A veterinary oncologist is the best source of information regarding chemotherapy drugs.
Dogs may experience weight loss due to the presence of the cancer. Post-surgical pain, lack of appetite and the side effects of the chemotherapy drugs, such as vomiting and nausea, may also occur. It’s important to provide nutritional support to decrease post-surgical complications, improve quality of life and increase response to therapy.
The prognosis depends on the location of the tumor, extent of the disease, general health of the pet and spreading of cancer to other organs. If bone cancer has spread to other organs or limbs, the prognosis could be poor. A patient with an amputated leg doesn’t reduce the quality of life for your dog, but it does depend upon each individual pet.
There’s a website called Tripawds, which is a wonderful source for dog owners who have gone through an amputation to share their stories. Although osteosarcoma is not preventable, effective treatments and early diagnosis can improve your dog’s life.
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